Reduction drive for variable condensers



Aug. 1, 1939. v. PETERSEN REDUCTION DRIVE FOR VARIABLE CONDENSERS Filed July 9, 1934 2 Sheets-Sheet 1 H E 5 R E w m T N E N V ATTORNEY 2 Sheets-Sheet 2 IN VlzNTOR VALEHTIH PETERSEN A TTUANE Aug. 1, 1939. v. PETERSEN REDUCTION DRIVE FOR VARIABLE CONDENSBRS Filed July 9, 1934 If Y ' AllIo-l,

UNITED STATES PATENT OFFICE REDUCTION DRIVE FOB VARIABLE OONDENSERS 17 Claims.

This invention relates to reduction drives for variable condensers.

The invention has peculiar adaptability for application in variable condensers for radio sets. Especially with the high degree of accuracy sought with the increased popularity of so-called short-wave" radio broadcasting and reception, many attempts have been made to secure a high degree of reduction between the manipulating knob fingered by the one adjusting the apparatus .to a desired wave-length and the shaft of such element as the rotor of a variable condenser, by which "tuning" may, either in whole or in part, be carried out. Such attempts have generally followed the usual trend oi larger and longer gear. trains, or the use of gears so large in diameter that special fittings are necessary properly to associate all the elements in position to effect the desired reduction.

The simple reduction obtained from a usual gear train, requiring, as it does, special mountings upon the condenser, introduces space problems of an undesirable character. The present-day trend, is toward decreasing, to as large a degree as 2 possible, the extent of each element, as, for instance, where radio-receiving apparatus is installed in automobiles. In such situations, space is at a premium. There the ordinary gear train, because of its great bulk and complexity of parts, becomes an inefllcient and undesirable means for the purpose indicated. One of the many problems thus met in providing a suitable drive for a micrometrlc adjustment of the variable element has been to accomplish this result while assuring against slippage between the parts of the driving mechanism, as, for instance, by utilizing the positive non-slipping functions of gears.

Many of the designed drives mentioned have mountings requisite therefor which entail a large number of parts, in addition to the details of construction and of the many parts of the drive itself. The elimination or reduction of such large numbers of parts likewise becomes a muchsought-ior end.

In the case of the plate condenser most commonly used at the present time, the rate plates are designed to produce the so-called straightline" effect, where, of course, the plates are eccentrically mounted upon their shaft. In such case, there is desired a reduction system which would make possible the use of the same end plates for the condenser no matter what the direction of rotation of such plates might be.

Another type of reducing mechanism used re- (Cl. lb-10) noticeable, and will distort, for the operator, the

entire arrangement oi the apparatus. Where such mechanism is interposed beyond the dial in the drive for a cable, as, for instance, in connecl0 tlon with remote control for radio-receiving apparatus carried by automobiles, as above mentioned, no prediction can be made concerning the divergence between successive readings of the dial and, therefore, its elimination as a guide 01' ii any worth-while character.

It is an object of the invention to provide a gear drive adapted for use in connection with condensers of the variable type. where such drive is capable of effecting a very high degree of re- 5) duction, even though the parts are contained within but a small portion of the space requisite for ordinary gear drives. As a feature of such drive is the fact that no greater space requirement, radially away from the condenser shaft, is involved than that set up by the rotating plates themselves. Thus, where such a drive is introduced, no enlargements or similar distortions of the casing or cabinet are involved. Thus, the extent of the elements necessary for such drive 3 may be even less than the extent of the rotor plates themselves.

It is an object, of the invention to provide, in a gear drive of the type "indicated, mechanism whereby a coarse adjustment or micrometer adjustment may be obtained at will, all while using substantially the same elements, and both the micrometer adjustment and the coarse adjustment being obtained positively, as by a positively geared drive, without opportunity for slippage.

It is an object of the invention to provide a reduction drive, especially adapted for accurately adjusting the rotors of variable condensers, which embodies in itself elements capable of completely housing, out of sight, moving parts of the drive, 5 and thus also guarding such members against foreign particles which might interfere with the proper operation of the apparatus. Since the drive, in one of its specific phases, is designed to utilize annular gears in a novel manner, these gears may be disposed in opposed relationship to each other, thus forming a chamber not open to entry of such particles. At the same time, such opposed members may constitute contact surfaces impartingto the apparatus suilloient irictiontominimiaaandeventoeliminatatheeffects of back-lash. Simultaneously. these contactedsuriacesmayserveasaccuratestopafor lining up the parts of the condenser.

In this relation, it is an obiect of the invention to provide a reduction gear drive, especially adaptable for variable condensers, the elements of which drive are capable of assembly by simple manipulations. without any great degree of technical skill, and with a small number of parts, so that, merely by bringing the several elements into a proper association, one with the other, the final apparatus is erected.

A multiplicity of stamping operations for the production of a low-priced article such as a condenser is, of course, undesirable. However. as the market, in connection with the straightline" plate condenser, requires the drive for the rotor to be clockwise or counterclockwise from minimum to maximum, for different d of the radio-receiving or similar apparatus, there arise different specifications for the end plates of such condensers. In such end plates are provided the bearings for the rotor shafts. The position of such bearings, by the very construction of the rotor plates. cannot be centrally of the end plates. 1!, in addition, it is required that one of the end plates also provide a mounting for elements of the reduction drive, then the punching of the two end plates for the same condenser, or for two condensers wherein the plates rotate oppositely to obtain the same adjusted condition, cannot be the same. Therefore, for each distinct job lot, wherein differences of this character are to exist, it becomes requisite to provide many differently punched end plates.

It is an object of the invention to provide a reduction gear drive for plate condensers of the type indicated by means of which drive but a single mounting hole is required properly to assemble the entire drive mechanism on such end plates. Thus is made possible the interchangeable use of such plates, whether the rotor of the condenser is intended to rotate in one direction or another toobtain the same character of adjustment in the normal operation of the condenser.

It is an o ect of the invention to provide a reduction ve for condenser rotors which positively locks the rotor against rotation under force acting directly upon the rotor itself, and only permits rotation of such rotor upon application of a proper force to a manipulator provided especially for that purpose.

Other objects of this invention will hereinafter be set forth, or will be apparent from the descrlption and the drawings, in which are illustrated certain embodiments of apparatus capable of demonstrating the invention.

The invention, however, is not intended to be restricted to any particular construction or arrangement of parts, or to any particular applica tion of such construction, or to any specific manner of use, or to any of various details thereof herein shown and described, as the same may be modified in various particulars, or be applied in many varied relations, without departing from the spirit and scope of the claimed invention, the embodiments herein illustrated and described being merely to demonstrate certain of the principles of the invention by some oi the possible forms and modifications in which physically the invention might be embodied.

On the drawings, in which the same reference characters refer to the same parts throughout,

and in which are disclosed such tive embodiments:

Hg. 1 is an elevational view. illustrating the application of features of the invention to a condenser assembly, parts being broken away;

Fig. 2 is a vertical sectional view, axially through an assembly similar to that shown in Fig. l, to an enlarged scale. illustrating the construction of a gear drive embodying features of the inventlon, portions being shown in elevation, and parts being broken away;

Fig. 3 is a sectional view, taken vertically through Fig. 2, substantially on the line H;

Fig. 4 is an elevational view, taken at the left end of Fig. 1, but only of the shaft end-plate;

Fig. 5 is a vertical sectional view, substantially axially of the condenser shaft in Fig. 1, and medially of the plate shown in Fig. 4, showing in detail the manner in which the shaft is assembled;

Fig. 6 is a vertical sectional view, on the line 66 of Fig. 2;

Fig. '1 is a side elevational view, illustrating a system for remote control of a condenser, the apparatus being broken away in section to illustrate the construction thereof;

Fig. 8 is a detail vew, taken from the righthand end of Fig. 7, part oi the casing being broken away to illustrate a portion of the construction thereof; and

Fig. 9 is a diagrammatic view, illustrating a method of dial drive directly from the reducing drive mechanism.

In the apparatus shown in Fig. 1, appears a condenser III of customary construction. having stator plates I2 and rotor plates M. The rotor plates are mounted upon a shaft it in any wellknown manner, the shaft being carried between end plates l8 and 20 in any desired manner, one such manner being hereinafter described. At one end 22 of the shaft, as, for instance, that end associated with plate 20, is a reduction drive 24. which includes an operating knob 26.

In the type of drive 24, here shown, there is included an annular gear 28 which may be mounted upon or made a part of a disk II. For simplicity of construction it is desirable to make gear 28 and disk Ill as a single element as, for instance, by die-casting. Disk "I is provided with suitable means so that it and its associated gear 28 may be mounted upon shaft end 22'. In this case, the mounting means takes the form of an opening 32, non-circular in contouring, and formed centrally of disk Ill. Shaft end 22 may be shouldered or otherwise given a cross-section at its extreme end so that the shaft end may be inserted into and fit snugly and tightly in the opening. A shoulder 34 may thus be provided on the shaft to limit movement of the disk. If desired, the shaft end may be swaged or otherwise the disk or the shaft end may be operated upon tightly to unite disk and shaft end for movement together.

Opposed to gear 28 is anbther annular gear 38, here shown as a part of manipulator 3B. Annular gear 36 may be supported with the manipulator in any desired manner, as, for instance, by being secured to or being made a part of wall 40 of the manipulator. This like wise may simply be accomplished by making the manipulator and gear 36 in the same manner indicated for gear 28 and disk 30.

Arranged in association with end plate 20 is an escutcheon plate 42. To permit this association, plates to serve as end plates are each provided with an opening 44 large enough to recelve snugly the annular flange 46. This flange extends from the escutcheon to deflne shoulder 48, the face of which is brought into abutment with the face of plate 28. Suitable means for retaining the plate in an associated relation may be provided. For instance, in the rim portion 88 of the plate may be provided openings 82 for the reception of securing devices 84 such as screws for anchoring plate 42 to plate 28.

Escutcheon plate 82 may include an inwardly turned annular flange 5!. Manipulator 28, on the other hand, in that portion directed away from wall 88, may have a shouldered portion 58. This shouldered portion is of such diameter as to be received snugly through opening 88 defined by flange 88. End face 82 is b.'ought into abutment with the inner face of flange 58 and, together with other elements of the apparatus to be described, serves to locate, in this embodiment, the plates of the rotor with relation to the plates of the stator. The annular edge of flange 88 thus provides a bearing for the manipulator, and also restrains the manipulator against outward movement.

Plates, such as those described to serve for end plate 28, may, merely by turning them over, serve for end plate l8. In such event, opening 48 may be straddled by a resilient strap 84, retained by suitable securing means, such as the screws. 88. Strap 84 may have formed therein a depression 88 for the reception of a ball III which then cooperates with a like recess 12 in the end of shaft I8, thus providing a ball thrust bearing for the shaft in cooperation with the resiliency of strap 88. However, in most instances, a separate plate in which there is formed an opening smaller than opening it will serve as plate I8. The same plate will function for plate 28, in any event, whether it is intended that rotor plates ll rotate clockwise or counterclockwise. This result is derived from the fact that but the one opening 44 is requisite for a proper mounting of the drive. By a mere reversal of the face of such an end plate, the axial position of opening N is adjusted for the required type of drive.

As shown in Fig. 2, disk 38 and wall 48 may be of such extent as to be in actual contact, one with the other. Their frictional contact, as can readily be understood, will be effective to counteract the customary eflects of backlash in gears. At the same time, to reduce the frictional component, face Il may be cut away, as at I6, to free it of contact with wall 48 and also gear member 18. The association of the faces of disk 38 and wall 48 is such as to define a chamber 88 between them, within which gear member 18 is contained and movable.

Gear member I8 may be made in any desired manner as, for instance, by die-casting. It is also possible to fabricate it from a plurality of distinct members, retained together. Gear member I8 is formed to define a pair of gears 82 and 84. When assembled as shown, gear 82 engages annular gear 28, and gear 84 engages annular gear 38.

Manipulator 38 may include a hub 88, to provide a bearing for a spindle 88. The spindle extends through the hub to a position immediately in association with gear member 18, where eccentric 98 is defined. A recess 92 in manipulator 38 may, with the formation of the spindle and of the eccentric, define a race for balls 94, thus again making provision for an accurate positioning of the shaft in relation to its several associated parts.

Gear member II is formed centrally thereof with a circular bearing opening 88 within which the eccentric is received. A pin 88, arranged to be coaxial with spindle 88, extends beyond eccentrio 88 to be received in a bore I88 in shaft end 22. A ball I82 in the bore may provide a suitable end thrust bearing for the spindle. In this manner, the spindle is mounted in bearings, its ends being carried in hub 88 and shaft l6.

Spindle 88 may extend forwardly beyond hub 88, there to have mounted thereon operating knob 28. Suitable means may be provided for permitting assembly and removal of the knob at will. In this case, a set-screw I88 is shown engaged through the knob and against the shaft end. In turn, a cylindrical extension I88 from the manipulator may provide for the reception of an actuating ring I88, likewise removably secured to the extension by any suitable means, in this case, set-screw III. Inner face 2 of ring I88 may be brought up closely to the outer face of flange 58. A groove Ill may be provided in that face, within which may be disposed a spring II8, preferably of the leaf variety.v This spring will then direct its force against flange 58, resisting relative movement of the manipulator with relation to the escutcheon plate.

As shown in Fig. 3, annular gears 28 and 28, of different diameters, are substantially coaxial. The diameters of gears 82 and 84 are such that, when member 18 is assembled upon eccentric 88, these gears will be tangent to, and, therefore, their teeth will be in mesh with the teeth of, their respective annular gears. 0n rotation of spindle 88, eccentric 98 will, therefore, cause gear member T8 to rotate eccentrically within the housing between the annular gears. However, throughout the movement of the eccentric, the gears will remain constantly in mesh.

Owing to the eccentricity, gears 82 and 84 may not be of the same diameter as their respective annular gears. As the eccentricity decreases, this condition naturally would be approached. As appears further herein, with such decrease of eccentricity, the degree of reduction is increased. Therefore, if a greater degree of reduction is desired, operating with the same annular gears, it is necessary merely to provide a smaller eccentric and a diflerent gear member 18.

If it be desired to operate a dial in conjunction with the construction shown in Fig. 2, many different methods may be followed. One suggested by the specific construction herein set forth involves making portion IIB of escutcheon plate 42 long enough to permit the formation of a slot I28 therethrough. This slot is made slightly greater in extent than 180. A prong I22 may be applied to, or be made a part of, disk 38, this prong being passed through slot I28 to extend externally of the housing formed by the escutcheon plate. An annular plate I 24, carrying proper indicia, is then secured to the extending end of prong I22 in any desired manner. A guideway I28 may be formed on the opposed section I28 of portion H8. The freely hanging plate is restrained against movement other than rotational by the cooperation of the guide therewith.

Since, in certain assemblages, the actuating ring I88 and knob 28 would extend beyond the panel I38 of a cabinet (here shown dotted to represent a relative position), the dial produced by plate I24 would be behind the panel, and might cooperate with an opening I32 through the panel for a proper reading of the position of the stator plates. Prong III, in making contact with the ends of slot I. would thereby limit the movement not only of the dial, but also of the rotor, eliminating the necessity for stops upon the plates themseiveaorupontheshafhasinmanypres ent-day constructions.

Whichever of the actuating elements, that is, actuating ring IOI or knob 20. is propelled, the dial will at all times indicate positively the actual position of plates II. By grasping actuating ring I" and imparting to it sufllcient force to overcome the frictional resistance of spring III, the gear train between gear ll, gear member II and gear II will be locked. and the entire assembly. including shaft I6, rotated, thus making it possible to obtain a rough adjustment when such is desired. When an approximate position has thus been attained, as indicated by dial plate I, actuating ring Illl is released, and knobactuated. effecting the micrometer adjustment sought in such apparatus to obtain an exact positioning of the rotor plates.

To assemble the construction shown in Fig, 2, after strap 04 has been applied to its end plate II, and the shaft end and its ball properly associated with the ball-receiving depression 88, the drive is assembled. Previously, however, manipulator ll, without its ring III, has been assembled in escutcheon plate I! by passing cylindrical extension II! through opening ll. Then ring III is slipped over extension III, and fixed in position, spring I I! being simultaneously located in its groove and against the flange face. Spindle 88 is dropped through the bore of hub II, the balls are politioned in race If. and knob 2i assembled in position. Gear member 1! is now slipped over the spindle, drcpl l into simultaneous cocpcratbn with the eccentric and annular gee-r48.

Now, since disk ll and gear 2| have been assembled at the end of shaft II, the next operation is to bringpin ll into bore III, after the ball has been inserted therein, and to secure escutcheon plate ll to end plate It. The opposed faces of disk II and wall ll will now cooperate. together with the thrust bearing at strap I, to retain the rotor plates in a properly associated relation to the stator plates.

In the apparatus shown in Fig. 'l, the problem involved is in connection with remote control. especially adapted for use In radio sets in automobiles, or for similar purposes. In the construction shown, a casing I may be mounted in any desirable position, as on a suitable panel such as an automobile dash-board. This casing may include a base plate I38 and a cover plate I38, retained together by suitable means. such as screws I. Carried in a hearing I" in plate I38, and a bearing I, in the hub I of annular gear I, is a shaft I50. Intermediately of the shaft is provided an eccentric I82. The shaft extends beyond hub I is and plate I38 for the reception of a knob I54.

The shaft also extends beyond plate I to provide means for engaging a coupling III of a cable I". This cable extends to and is, in turn, coupled, at I", to a spindle I", which is supported in a bearing I in a cover plate I. Plate I66 has a. shoulder formation I for reception in an opening I III in end plate I'll of a condenser assembly I'll.

At casing ill, eccentric I52 supports gear member I16, composed of the united gears I'll and I'll, functioning to rotate them eccentrically while in engagement, respectively, with annular gears Ill and Ill. Annular gear III, in this case, is shown as formed as a part of base plate I"; and annular gear III, as a part of a member I. Hub I on member I is, in turn, provided with a hearing at an opening ill through cover plate Ill.

Associated with member II, as by being secured to the outer face Ill thereof, is a dial member I". A portion of member III is made visible through an opening I92 in cover plate Ill, this opening being protected by a suitable transparent window I to permit reading of the dial therethrough.

At spindle I02 there is provided an eccentric I substantially similar to eccentric III, and carrying a gear member I consisting of gears 2 and III. These gears are intermesbed with annular gears Ill and 208, annular gear 2" being formed integrally with cover plate I86, while annular gear I is formed as a part of a disk 208, secured to shaft III of the condenser assembly. Spindle end II! is carried in a recess 2 in the shaft end. As appears in Fig. 1, the total extent of the elements involved in the reduction drive, that is. the diameter of the largest element thereof, is hardly as large as the space required for a proper movement of the rotor plates of the condenser.

It can, therefore, be seen that, by introducing into the assembly. at casing I34, substantially the same relationship of gears and eccentric as in the assembly at gears Ill and 2B", the dial reading through opening I02 will be substantially continuously identical with the positioning of the plates at condenser assembly I'll. However, in order to produce a micrometer reading of even higher degree for the condenser, and taking into account the fact that most condenser rotors are stopped against rotation beyond 180, the ratio of reduction may be such that dial member III will rotate 360 for every 180 of shaft IIO.

In order to eliminate the necessity for stops upon the rotor of the condenser, with an arrangement of the character Just set forth, a pin 2" may be mounted in plate I" so as to engage with a pin III extending radially and mounted in any desired manner on member I. Thus, knob I will be stopped against a rotation of more than 360 in one direction, while the condenser coupled to it is likewise restrained against a rotation of more than 180.

In the construction shown in Figs. 2 and 3, it will be seen that the effective diameter of annular gear 2! is smaller than the diameter of annular gear 16. There results, from an arrangement of this character, that movement of knob 28 in one direction will effect movement of shaft IS in the same direction. In Fig. '7, the reverse condition is shown, where the effective diameter of annular gear 204 is less than that of gear 206. The same type of reduction will ensue, except that the rotation of knob I54 will be reversely of the rotation of shaft 2Ili.

In Fig. 9, is shown a construction for driving a dial not concentrically disposed with relation to the condenser shaft. In this case, member 220, which has as a part thereof the annular gear directly coupled to the condenser shaft, may be provided with external teeth 222. With these teeth are then engaged a spur gear 2N, carried by a shaft 228. On shaft 226, or, as desired, upon a still more remotely disposed member, is a dial 228, positioned thus in accordance with the position of the rotor plates. Teeth 222 may be formed as a part of the die-casting operation indicated for the production of member II.

It has been found that apparatus of the type herein discussed responds to the following formula:

Furthermore, this apparatus responds to a for-- mula of the following character:

2X(BE) (s- 2102 where X=eccentricity.

From this formula, it is clearly understandable that, as the eccentricity decreases, the degree of reduction increases. Also. it is seen that the size of the annular gear fixed to the rotor becomes an important element, as, with increase of its diameter, the reduction factor increases until a point where the two annular gears are of the same diameter when no relative movement of the annular gears may occur.

Many other changes could be effected in the particular apparatus designed, and in the methods of operation set forth, and in the specific details thereof, without substantially departing from the invention intended to be defined in the claims, the specific description herein being merely to illustrate operative embodiments for carrying out the spirit of the invention.

What is claimed as new and useful is:

l. A reduction drive for variable radio-tuning apparatus including a substantially stationary portion, a portion movable relatively to the stationary portion, and a shaft for the movable portion of the tuning apparatus; said drive including a pair of manipulators, and means interconnecting the manipulators and the shaft; the interconnecting means comprising elements including a gear and an annular gear which move relatively to each other when one of the manipulators is the force-transmitting agent but look against movement relative to each other when force is applied to the other manipulator; said other manipulator normally providing means for retaining one of the elements stationary with relation to the stationary portion.

2. A reduction drive for variable radio-tuning apparatus including a substantially stationary portion, a portion movable relatively to the stationary portion, and a shaft for the movable portion of the tuning apparatus; said drive including a pair of manipulators, and means interconnecting the manipulators and the shaft; the interconnecting means comprising elements including a gear and an annular gear which move relatively to each other when one of the manipulators is the force-transmitting agent but look against movement relative to each other when force is applied to the other manipulator; said other manipulator being fixedly engaged with and normally providing means for retaining one of the elements stationary with relation to the stationary portion.

3. A reduction drive for variable radio-tuning apparatus including a substantially stationary portion, a portion movable relatively to the stationary portion, and a shaft for the movable portion 0! the was; apparatus: said drive including a pair of manipulators, and means interconnecting the manipulators and the shaft: the interconnecting means comprising elements including a gear and an annular gear which move relatively to each other when one of the manipulators is the force-transmitting agent but lock against movement relative to each other when force is applied to the other manipulator: said other manipulator being fixedly engaged with one of the elements; and means co-operating with said other manipulator normally to provide means for retaining said other manipulator and said element stationary with relation to the stationary portion.

4. In a precision adjustment device, the combination of an instrument mounting having mounted thereon a rotary part to be angularly adjusted, a knob and a manipulator for controlling the angular adjustment of the rotary part, a plurality of elements between the knob and the manipulator, and between them and the rotary part, for transmitting motion from the knob and the manipulator to the rotary part, and means on one of the elements and the instrument mounting for limiting in its angular movement the rotary part with relation to the instrument mounting under the action of either the manipulator or the knob.

5. In a precision adjustment device, the combination of an instrument mounting having mounted thereon a rotary part to be angularly adjusted, a knob and a. manipulator for controlling the angular adjustment of the rotary part, a plurality of elements between the knob and the manipulator, and between them and the rotary part, for transmitting motion from the knob and the manipulator to the rotary part, one of the elements being fixedly associated with the rotary part, and means on that element and the instrument mounting for limiting the angular movement of the rotary part with relation to the instrument mounting.

6-. In a precision adjustment device, the combination of an instrument mounting having mounted thereon a rotary part to be angularly adjusted, a knob and a manipulator for controlling the angular adjustment of the rotary part, a plurality of elements between the knob and the manipulator, and between them and the rotary part, for transmission motion from the knob and the manipulator to the rotary part, one of the elements being fixedly associated with the rotary part, means for indicating the angular position of the rotary part, the indicating means being directly controlled by that element, and means on that element and the instrument mounting for limiting the angular movement of the rotary part with relation to the instrument mounting.

'1. In a precision adjustment device, the combination of an instrument mounting having mounted thereon a rotary part to be angularly adjusted, a knob and a manipulator for controlling the angular adjustment of the rotary part, a plurality of elements between the knob and the manipulator, and between them and the rotary part, for transmitting motion from the knob and the manipulator to the rotary part, one of the elements being fixedly associated with the rotary part, means for indicating the angular position of the rotary part, the indicating means being carried directly on that element, and means on that element and the instrument mounting for limiting the angular movement of the rotary part with relation to the instrument mounting. 7

8. In a precision adjustment device, the combination of an instrument mounting having mounted thereon a rotary part to be angularly adjusted, a knob and a manipulator ior controlling the angular adjustment the rotary part, a plurality of elements between the knob and the manipulator, and between them and the rotary part, for transmiting motion from the knob and the manipulator to the rotarypart. one of the elements being associated with the rotary part to have the same angular movement as the rotary part, means for indicating the angular position of the rotary part, the indicating means being directly controlled by that element, and means on that element and the instrument mounting for limiting the angular movement of the rotary part with relation to the instrument mounting.

9. In a precision adjustment device, the combination of an instrument mounting having mounted thereon a rotary part to be angularly adjusted, a knob and a manipulator for controlling the angular adjustment of the rotary part, a plurality of elements between the knob and the manipulator, and between them and the rotary part, for transmitting motion from the knob and the manipulator to the rotary part, one of the elements being associated with the rotary part to have the same angular movement as the rotary part, means for indicating the angular position of the rotary part, the indicating means being carried directly on that element, and means on that element and the instrument mounting for limiting the angular movement of the rotary part with relation to the instrument mounting.

10. In a precision adjustment device, the combination of an instrument mounting having mounted thereon a rotary part to be angularly adjusted, a knob and a manipulator for controlling the angular adjustment of the rotary part, a pair of annular gears positioned substantially coaxially, spur gear means within the annular gears for engaging both annular gears simultaneously, the knob having means for carrying the spur gear means and for rolling the spur gear means simultaneously over both the annular gears, the manipulator being carried on one of the annular gears, means between the manipulator and the instrument mounting for restraining movement oi the annular gear carrying the manipulator when the knob is rotated, and means on one of the elements and the instrument mounting for limiting the angular movement of the rotary part with relation to the instrument mounting.

11. In a precision adjustment device, the combination of an instrument mounting having mounted thereon a rotary part to be angularly adjusted, a knob and a manipulator for controlling the angular adjustment of the rotary part, a pair of annular gears positioned substantially coaxially, spur gear means within the annular gears for engaging both annular gears simultaneously, the knob having means for carrying the spur gear means and for rolling the spur gear means simultaneously over both the annular gears, the manipulator being carried on one of the annular gears, and means between the manipulator and the instrument mounting for restraining movement of the annular gear carrying the manipulator when the knob is rotated.

12. In a precision adjustment device, the combination of an instrument mounting having mounted thereon a rotary part to be angularly adjusted. a knob and a manipulator for controlling the angular adjustment of the rotary part, a pair or annular gears positioned substantlalLv ooaxially, spur gear means within the annular gears for engaging both annular gears simultaneously, the instrument mounting having a housing for the annular gears, the knob having means for carrying the spur gear means and for rolling the spur gear means simultaneously over both the annular gears, the manipulator being carried on one of the annular gears, and means between the manipulator and the housing for restraining movement of the annular gear carrying the manipulator when the knob is rotated.

13. In a precision adjustment device, the combination of an instrument mounting having mounted thereon a rotary part to be angularly adjusted, a knob and a manipulator for controlling the angular adjustment of the rotary part, a pair of annular gears positioned substantially coaxially, spur gear means within the annular gears for engaging both annular gears simultaneously, the instrument mounting having a housing for the annular gears, the knob having means for carrying the spur gear means and for rolling the spur gear means simultaneously over both the annular gears, one of the annular gears having a portion extending through the housing, the manipulator being carried on said portion, and means between the manipulator and the housing for restraining movement of the annular gear carrying the manipulator when the knob is rotated.

14. In a precision adjustment device, the combination of an instrument mounting having mounted thereon a rotary. part to be angularly adjusted, a knob and a manipulator for controlling the angular adjustment of the rotary part, a pair of annular gears positioned substantially coaxially, Spur gear means within the annular gears for engaging both annular gears simultaneously, the instrument mounting having a housing for the annular gears, the knob having means for carrying the spur gear means and for rolling the spur gear means simultaneously over both the annular gears, one of the annular gears having a portion extending through and journalled in the housing, the manipulator being carried on said portion, and means between the manipulator and the housing for restraining movement of the annular gear carrying the manipulator when the knob is rotated.

15. In a precision adjustment device, the combination of an instrument mounting having mounted thereon a rotary part to be angularly adjusted, a knob and a manipulator for controlling the angular adjustment of the rotary part, a pair of annular gears positioned substantially coaxially, spur gear means within the annular gears for engaging both annular gears simultaneously, the instrument mounting having a housing for the annular gears, the knob having means for carrying the spur gear means and for rolling the spur gear means simultaneously over both the annular gears, one of the annular gears having a portion extending through the housing, the manipulator being carried on said portion, and means between the manipulator and the housing and engaging the outer face of the housing for restraining movement of the annular gear carrying the manipulator when the knob is rotated.

16. In a precision adjustment device, the combination 0! an instrument mounting having mounted thereon arotary part to be angularly adjusted, a knob and a manipulator for controlling the angular adjustment of the rotary part, a pair of annular gears positioned substantially coaxially, spur gear means within the annular gears for engaging both annular gears simultaneously, the instrument mounting having a housing for the annular gears, one 01 the annular gears having a portion extending through the housing, the manipulator being carried on said portion, an eccentric having the spur gear means journalied therein so that on rotation of the eccentric the spur gear means will be rolled simultaneously over both annular gears, a shaft extending from the eccentric and through that annular gear, the knob being carried by the shaft, and means between the manipulator and the housing and engaging the outer face of the housing for restraining movement of the annular gear carrying the manipulator when the knob is rotated.

1'1. In a precision adjustment device, the comblnation of an instrument mounting having mounted thereon a rotary part to be angularly adjusted, a knob and a manipulator for controlling the angular adjustment of the rotary part, a pair of annular gears positioned substantially coaxially, spur gear means within the annular gears for engaging both annular gears simultaneously, the knob having means for carrying the spur gear means and for rolling the spur gear means simultaneously over both the annular gears, the manipulator being fixedly associated with one of the annular gears to rotate therewith, and means ior restraining the annular gear having the manipulator associated therewith against movement when the knob is rotated.

VAIENTIN PETERSEN.

Patent No. 2,167,677.

August 959.

VALENTIN PETERSEN It is hereby certified that error appears in the printed specification of the above numbered patent requiring correction as follows: Page 1, first column, line 25, after the word "trend" strike out; the comma; page 5, second column, line 52, claim for "transmission" read transmitting; page 6, first column, line 10, claim 8, for "transmiting" readtransmitting; and that the saidLetters- Patent should be read with this correction therein that the same may conform to the record of the case in the Patent Office.

Signed and sealed this 6th day of February, A. D. 191;,0.

(Seal) Henry Van Arsda1e,. Acting Commissioner of Patents.

bination 0! an instrument mounting having mounted thereon arotary part to be angularly adjusted, a knob and a manipulator for controlling the angular adjustment of the rotary part, a pair of annular gears positioned substantially coaxially, spur gear means within the annular gears for engaging both annular gears simultaneously, the instrument mounting having a housing for the annular gears, one 01 the annular gears having a portion extending through the housing, the manipulator being carried on said portion, an eccentric having the spur gear means journalied therein so that on rotation of the eccentric the spur gear means will be rolled simultaneously over both annular gears, a shaft extending from the eccentric and through that annular gear, the knob being carried by the shaft, and means between the manipulator and the housing and engaging the outer face of the housing for restraining movement of the annular gear carrying the manipulator when the knob is rotated.

1'1. In a precision adjustment device, the comblnation of an instrument mounting having mounted thereon a rotary part to be angularly adjusted, a knob and a manipulator for controlling the angular adjustment of the rotary part, a pair of annular gears positioned substantially coaxially, spur gear means within the annular gears for engaging both annular gears simultaneously, the knob having means for carrying the spur gear means and for rolling the spur gear means simultaneously over both the annular gears, the manipulator being fixedly associated with one of the annular gears to rotate therewith, and means ior restraining the annular gear having the manipulator associated therewith against movement when the knob is rotated.

VAIENTIN PETERSEN.

Patent No. 2,167,677.

August 959.

VALENTIN PETERSEN It is hereby certified that error appears in the printed specification of the above numbered patent requiring correction as follows: Page 1, first column, line 25, after the word "trend" strike out; the comma; page 5, second column, line 52, claim for "transmission" read transmitting; page 6, first column, line 10, claim 8, for "transmiting" readtransmitting; and that the saidLetters- Patent should be read with this correction therein that the same may conform to the record of the case in the Patent Office.

Signed and sealed this 6th day of February, A. D. 191;,0.

(Seal) Henry Van Arsda1e,. Acting Commissioner of Patents. 

